General Introductory Notes and Acknowledgements

The Trial Gardens for seasonal color plant materials are located at NC State
University within the JC Raulston Arboretum (JCRA) in Raleigh. The JCRA is an
eight acre site administered by the Department of Horticultural Science and
located on 35° 47'N latitude, longitude 78° 42' W, with
an elevation of 400 feet.

Plants to be entered into our trials are received in a variety of ways. About
half are germinated from seeds while the remainder originate as rooted cuttings
or established cell plugs. Virtually all are grown within controlled greenhouse
environments prior to placement in protected outdoor structures for hardening
off. They were planted into their permanent trial bed locations on November
6, 2008. The predominant plant spacing in the trials was 18 inches × 12
inches (in-row × between-row spacing). Seven plants of each entry were
used to evaluate landscape performance and ratings were taken weekly.

Acknowledgements

We thank the following companies for their support of material donations:

We are especially thankful to the departmental staff and the volunteers of
the JC Raulston Arboretum who assisted in transplanting the annual beds. We
couldn't have done it without you all!

Understanding Our Data

Number of Weeks in Flower

This is recorded as the total number of weeks in flower throughout the entire
season. It should give you an idea of whether or not a plant is best used for
the whole season or as a "fill-in" for special displays. Obviously,
those species grown for foliage interest alone, e.g. Acalypha, may
score poorly in this column and should not be rejected based on this value alone!

Weekly Ratings

Plants were given a visual rating weekly by the same person beginning November
25, 2008, (about three weeks after planting) through April 9, 2009. The overall
rating was based on plant performance and appearance, including floriferousness,
plant size and shape, and freedom from insect and disease problems. The rating
scale ranged from 1 (very poor) to 5 (excellent)
with 0.5 unit increments possible; a 0 rating indicated
that all plants of the cultivar trial died.

Summaries of Weekly Ratings

The first statistic that readers run to is likely the "all season
average." This value represents overall performance for the entire
season. However, realizing that there are many species/cultivars which may do
better in one part of the growing season versus another, we also provide an
"early season average" and "late
season average" for each entry. The former is the average of
the first 8 weeks of the evaluation period and the latter represents the end
of the season. This information may be useful in planning short term plantings
with high impact as well as for studying temperature preferences, life cycle
changes, and/or the impact of photoperiod on plant performance. The "number
of weeks rated above 3" gives you an idea of how consistently
throughout the season an entry is an exemplary performer.

The Lists You'll Find In This Report

• "The
Top 10" - this list shows the species/cultivars with the top
ten "All Season Averages." These were our best overall performers.
When the list exceeds ten, there were ties.

• "Leaders
of the Pack" – lists all species/cultivars with an "All
Season Average" of 3.0 or better. We consider this the arbitrary cutoff
rating for a "significant performer" in Raleigh. This list shows
all your best choices for planting, listed by plant name.

• "Leaders
of the Pack – Early Season" – this shows entries
with "Early Season Averages" of 3.0 or better based on the first
eight weeks of evaluation. This group may prefer warmer temperatures or only
have a relatively short ornamental life, and might not show up on the "Leaders
of the Pack" list above.

• "Leaders
of the Pack – Late Season" – this shows entries with
"Late Season Averages" of 3.0 or better based on the end of the
season evaluations. They may prefer warm temperatures or flower as daylengths
start to lengthen, again sometimes precluding them from inclusion on the overall
"Leaders of the Pack" list.

• "Best
of Breed" - shows the best performing cultivars in each species.

• "Summary
by Series" - groups the information for cultivar series where
appropriate. This can be a quick reference for related cultivars as well as
a handy tool to judge the general performance of an entire series offered by
a breeder/company.

Want Additional Copies of this Report?

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www.ncsu.edu/jcraulstonarboretum

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The Average Monthly Precipitation and
Temperature for the Winter 2008-2009 Trials

Immediately after planting, we experienced a prolonged cold period that is not visibly represented in the temperature chart above. This cold snap resulted in the death of several entries. Winter also brought us two additional extended cold periods and two measurable snowfalls—the first snow in five years.

Variance

Variance: The Best of Uniformity

Sometimes I think that the one number most often overlooked in our report is
the variance. Go to the "Leaders of the Pack" data
tables and look for its column. The term itself may be intimidating in light
of its mystery, but need not be as it can be most informative. Simply put, the
lower the variance, the most alike all plants are in the group evaluated, and
hence the greater the uniformity. For so many in the commercial landscaping
sector, they live and die by uniformity because appearance can be everything.
So, by using a selected variance value of 0.1 as our very tough cut-off, we
can really see which plants are setting the standard for superb uniformity.

Variance: All Over the Page

Whereas small variance values indicate excellent uniformity, the opposite can
point out cultivars with a "mind of their own!" They are not necessarily
a poor choice, just not ruler perfect. In this case, plants with variance values
of 1.0 or more were highlighted for great differences observed during the season.

Seed and Plant Material Sources

Please get in touch with these companies if you have specific questions regarding
individual species and cultivars.